Transwell permeable polycarbonate inserts 0.4 μm

The human colon adenocarcinoma cell line, Caco-2, was purchased from the Cell Bank of the Chinese Academy of Sciences (Shanghai, China). Dulbecco's modified Eagle's medium (DMEM), Hank's buffered salt solution (HBSS), antibiotic solutions (100,000 U/L penicillin and 100,000 mg/L streptomycin), fetal bovine serum (FBS), 100× nonessential amino acids, 100× penicillin and streptomycin, and 0.25% trypsin with ethylenediaminetetraacetic acid (EDTA) were from Invitrogen Corp. (Carlsbad, CA). Transwell permeable polycarbonate inserts (0.4 μm) and 12-well cell culture plates were obtained from Corning. Verapamil, MK 571, indomethacin, benzbromarone, apigenin, sodium vanadate, and cimetidine were obtained from Aladdin Industrial Inc. (Shanghai, China). Loganin (purity > 98.0%) and puerarin (internal standard (IS), purity > 98.0%) were obtained from the National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). All other reagents were of analytical grade.

Transwell permeable polycarbonate inserts (0.4 μm) and 12-well cell culture plates were obtained from Corning. (Cambridge, MA, USA). The Caco-2 cell line was generously provided by the Cell Bank of the Chinese Academy of Sciences (Shanghai, China). Dulbecco’s modified Eagle’s medium (DMEM) was obtained from Gibco Laboratories (Life Technologies Inc., Grand Island, NY, USA). Hanks’ balanced salt solution (HBSS, powder form) was obtained from Sigma Chemical Co. (Deisenhofen, Germany). Fetal bovine serum was purchased from HyClone (Logan, UT, USA). The 100× nonessential amino acids, 100× penicillin and streptomycin, 0.25% trypsin with ethylene-diaminetetraacetic acid (EDTA), 1 M 4-(2-hydroxyethyl)-1-piperazi- neethanesulfonic acid (HEPES), and bovine serum albumin were purchased from Invitrogen Corp. (Carlsbad, CA, USA). Verapamil, MK571, indomethacin, benzbromarone, apigenin, sodium vanadate and cimetidine used in this study were obtained from Aladdin Industrial Inc. (Shanghai, China). Morroniside (purity > 98.0%) and loganin (internal standard (IS), purity > 98.0%) were obtained from the National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). All other reagents (typically of analytical grade or better) were used as received.